The cost of power in the United States is one of the most expensive cost of living elements incurred by the consumer. This makes finding less expensive sources of electricity of paramount importance for the continued economic vitality of the country. Depending mainly upon the geographic location and the source of power generation, these costs may vary considerably. This is clear from the following comparative listing of power sources, a five-year forecast of the estimated U.S. average power costs in dollars per kilowatt hour for most regular and renewable sources of energy as prepared by the U.S. Energy Information Agency (EIA) as of 2015:
Geothermal$.048/kwhOnshore Wind.074Hydro.083Conventional Coal.095Advanced Nuclear.095Biomass.100Advanced Turbine, Natural Gas.113Solar, Photovoltaic.125Offshore Wind.197Concentrated Solar Power.240
The above $/kwh listing represents the EIA's estimated levelized cost of electricity (LCOE) and is a measure of a power source which attempts to compare different methods of electricity generation on a comparable basis. It is an economic assessment of the average total cost to build and operate a power-generating asset over its lifetime divided by the total energy output of the asset over that lifetime. The LCOE can also be regarded as the minimum cost at which electricity must be sold in order to break-even over the lifetime of the project.
By comparison, the LCOE for several versions of this invention was estimated to be in the order of $0.045/kwh, or about the same low cost as geothermal.
Our above LCOE for this invention was computed on the same basis as that of the EIA in that our cost range consisted of the capital to build and to operate the present invention including all maintenance, overhead and interest expenses over the asset lifetime divided by the total energy output of the asset over that lifetime. Our estimates thus indicate that the present invention has the potential of saving the public substantial expenses for future power costs.
It has been well established that renewable energy is a more desirable power source alternative than other fuel means since it is much cleaner than fossil fuel, far safer than nuclear energy and is abundant. Solar, offshore and onshore wind projects require extensive areas for operation, may be environmentally disruptive and are generally expensive and considered by many to be unsightly. Geothermal, onshore wind and inland hydro may also be unsightly and environmentally disruptive but are the least expensive of the alternative energy power sources. However, they are less desirable for investment for generation purposes owing to the general scarcity of their areas for suitable economic operation. Thus marine currents offer attractive potential for a source of power since the cost will generally be lower for certain types, the systems are usually submerged out of sight and the area of suitable ocean current availability is the most extensive available. These factors probably account for the present increase in tidal current programs throughout the world although such programs may be problematic owing to high installation cost and environmental impact. However, at this time there are no known commercially active power generation systems designed for operating in the high seas in non-tidal areas except for this invention.
Excluding offshore wind projects, virtually all renewable ocean power generation systems in use today extract energy from tidal mechanisms that rely on water moving alternatively in two directions where the full generation of power is limited to somewhat less than a full day. Such systems are located at or near shallow edge water areas where environmental conditions may be disrupted and their presence may be unsightly. This is especially true of power generation systems requiring the building of extensive shoreline embankments or levees to form lagoons that temporarily retain and store incoming seawater for release during periods when the tide recedes. The lagoon systems can be unsightly and all are expensive to build because of the often extensive land work needed to build the levees. Such expenses must be passed on as the cost of power to the consumer. Other tidal systems may be comprised of a free standing submerged turbine generators that are mounted on large stands or on buried foundations located in shallow waters where there is a significant danger to marine life and may be a hazard to water sports and other surface activity. Tidal energy is harnessed in a cyclical manner from the incoming and outgoing currents resulting in a discontinuous pattern of electricity generated.
In the past, various patents have addressed the issue of using the hydrodynamic force of water to generate power. For example, U.S. Pat. No. 3,986,787 issued to Mouton and Thompson and published on Oct. 19, 1976, describes a platform upon which is mounted above water an electrical power generator connected by a drive belt to an underwater turbine wheel on a horizontal shaft that is coaxially mounted below the platform within an intake nozzle in a river current. The system is manually transported and anchored to the river bottom to a location where it remains floating at the surface where it may be subject to accident with surface marine traffic; it has no means of amplifying the ocean current speed.
U.S. Pat. No. 4,163,904 issued to Lawrence Skendrovic and published on Aug. 7, 1979, provides for a turbine plant anchored to the sea floor that provides for generating electrical power by means of the flow of coastal water currents. Each turbine plant has a large central opening within which is mounted a large turbine impeller. An electrical generator is mounted within the watertight housing of the plant adjacent to the central opening. The opening of the plant has a large diametrical forward entrance and a large diametrical rearward exit with a substantially central portion of smaller diametrical extent. The impeller of the turbine plant is mounted in the smallest diametrical extent of the opening. The contour of the opening provides for a Venturi effect increasing the efficiency of plant operation. The system is manually transported and anchored to the river bottom but has no means of amplifying the ocean current speed.
U.S. Pat. No. 4,219,303 granted to Mouton and Thompson and published on Aug. 26, 1977, calls for a power plant for the generation of electricity from the flow of water currents that uses turbine wheels within nozzles submerged in the water current, anchored to the bottom of the water course, as for example, the ocean, and self-buoyed to a level well below the water surface. Pairs of counter-rotating turbines are supported by their rims, which bear against friction drive wheels, which in turn drive electrical generators contained in water-tight deep-water machine rooms within the wall of the nozzle. The system is manually transported to the selected site then anchored to the sea bottom where the elevation of the system above the sea floor is manually set; it has no means of amplifying the ocean current speed.
U.S. Pat. No. 4,224,527 received by Jack E. Thompson and published on Sep. 23, 1980, wherein he describes a method of intensifying a relatively slow speed, substantially horizontal flow of a natural fluid, such as a tidal flow, as opposed to a tidal rise, or a river flow, the natural flow being used to turn about a substantially horizontal axis rotary means arranged to act directly on a working fluid, which may be the natural fluid, where the latter is a liquid, or a separate liquid, and force it through a pipe system to a flow intensifier in the form of a constriction anchored to the floor of the body of water. The working liquid is forced through the pipe system without the formation of a head, and can be used to drive means for generating electricity. Flow intensifying apparatus is also described using seawater as the natural fluid and either fresh water or the seawater as the working fluid. Several of the apparatus may be disposed to cause a vortex or maelstrom which then serves to drive the apparatus which must be set manually. It has no means of amplifying the ocean current speed and offers no protection for marine life.
U.S. Pat. No. 4,383,182 granted to Wallace W. Bowley and published on May 10, 1983 is based on energy being produced in a power producing module by means of a turbine energized by ocean currents where a shaft rotationally connecting the turbine to a pump then moves a system fluid that is conveyed from the power producing module to a separate power absorbing module by means of piping; the moving system fluid then drives a turbine in the power absorbing module where a turbine is axially connected to a generator that rotationally produces power. He relates that large quantities of power may be produced in this manner by coupling several such power producing modules to the power absorbing module and thence to a power grid for sales. The system must be transported and positioned manually; it has no means of amplifying the ocean current speed and offers no protection for marine life.
U.S. Pat. No. 7,768,145 received by Hector Fillipus, Alexander Van, Drentham Susman, Kenneth Stewart and Donald Stewart, published on Aug. 3, 2010, relates to an underwater turbine unit housed in a cylindrical body and connected rotationally to a electrical power generator mounted on the seafloor in shallow water to capture energy from reversing tidal ocean currents. A multiplicity of such turbine generators are connected to a power center for transfer by cable to shore. The system must be transported and positioned manually; it has no means of amplifying the ocean current speed and offers no protection for marine life.
US WO2015142737 A1 credited to James G. P. Dehlsen and published on Sep. 24, 2015, provides for a floating tower frame for a plurality of connected turbine systems placed in ocean currents for the purpose of generating electrical power or high pressure seawater for reverse osmosis or fresh water production from steady (gyre) or tidal currents. The subsea turbines are mounted near the base of a plurality of floating towers held in parallel between a horizontal truss structure above water and a horizontal wing at the base of the towers, below the surface. Part of the structure is above water and subject to the risk of an accident with marine traffic. Further, the system must be transported and positioned manually; it has no means of amplifying the ocean current speed and offers no protection for marine life.
U.S. Pat. No. 6,091,161 registered to James G. P. Dehlsen, James B. Dehlsen and Geoffrey F. Deane was published on Jul. 18, 2000. This art form may be described as two tethered, submerged, ocean current-driven turbines with counter-rotating, variable pitch blades. The two turbines are axially connected to separate electric generators and are joined by a water-wing like structure having a canard-like device located centrally on the wing to assist in controlling the depth of the system. This power-generating device may be set to a predetermined maximum depth and a predetermined minimum depth in addition to the selective setting of a sensing depth involving an ascend command or a descend command where the operating depth of the system is midway between the predetermined maximum depth and the predetermined minimum depth. Further, the system must be transported and positioned manually; it has no means of amplifying the ocean current speed and offers no protection for marine life.
U.S. Pat. No. 8,272,831 issued to Barry Johnston and published Sep. 25, 2012, is comprised of an apparatus for the generation of power from sea currents that includes an elongate, generally circular in cross section, free floating tubular buoyancy vessel having affixed to its underside on a mounting means, rotatable rotor blades. The rotor blades are connected to a power generating means whereby the movement of sea water currents across the rotor blades, drives them so as to generate power. The apparatus is tethered to the sea bottom or other fixed point where power is exported by cable attached to the tether line. The system must be transported and positioned manually; it has no means of amplifying the ocean current speed and offers no protection for marine life.